Consider the redox reaction as represented by the following equation: 12(aq) + 2S2O32-(aq) → 21–(aq) + S4O62-(aq). Which of the species in the equation is reduced?
- A. S4O62-(aq)
- B. S4O32-(aq)
- C. 12(aq)
- D. 1-(aq)
Which of the following cells produce electrical energy from chemical reactions?
l. Lead-acid battery ll. Dry cell III. Deniell cell IV Electrolytic cell
- A. l and ll only
- B. l, ll, and III only
- C. lll and IV only
- D. I and III only
Consider the reaction represented by the equation: N2O4(g) ⇌ 2NO2(g) ; ∆H = + x kJmol-1
What happens when the temperature is reduced at equilibrium?
- A. Concentration of N 2O4(g) decreases
- B. Concentration of N 2O4(g) increases.
- C. Pressure exerted by the gases increases
- D. Pressure exerted by the gases remains constant
The following factors affect the solubility of a solid in a given solvent except
- A. nature of solute
- B. nature of solvent
- C. pressure
- D. temperature
A substance is said to be impure if
- A. its melting point range is wide
- B. it dissolves in water with difficult
- C. it has a low melting point
- D. it is coloured
Which of the following compounds crystallizes without water of crystallization?
- A. MgSO4
- B. Na2CO3
- C. NaCI
- D. FeSO4
Which of the following acids would readily react with CaCO3 to liberate CO2?
- A. CH3COOH
- B. H2SO4
- C. H2SO3
- D. HNO3
The aqueous solution which has pH > 7 is
- A. FeCI3(aq)
- B. CuSO4(aq)
- C. KNO3(aq)
- D. Na2CO3(aq)
When heat is absorbed during a chemical reaction, the reaction is said to be
- A. adiabatic
- B. endothermic
- C. exothermic
- D. isothermal
Which of the following variables is a measure of the average kinetic energy of the molecule of a gas?
- A. Density
- B. Pressure
- C. Temperature
- D. Volume
Which of the following gases are arranged in increasing order of diffusion rate? [H = 1 .0; C = 12; N = 14; O = 16; S = 32]
- A. SO 2 O2, NH3 H2
- B. H2S,NH2,O2,SO2
- C. CO2,N2O,O2,SO2
- D. NH3,NO2,N2,CO2
The pressure exerted by a gas is a function of the
- A. total volume of the gas
- B. speed of the gaseous molecules
- C. mass of each gaseous molecule
- D. frequency of collision between gaseous molecules
Which of the following phenomenna lead to decrease in volume of a liquid in an open container?
- A. Brownian motion
- B. Diffusion
- C. Evaporation
- D. Sublimation
The gas law which describes the relationship between volume and temperature is
- A. Boyle's law
- B. Charles' law
- C. Dalton's law
- D. Graham's law
The percentage by mass of calcium in Ca(OCI)2 is [Ca = 40.0; CI = 35.5; O = 16.0]
- A. 28.0%
- B. 31.6%
- C. 43.8%
- D. 44.5%
The volume of 0.25 moldm-3 solution of KOH that would yield 6.5g of of solid KOH on evaporation is (K = 39.0; o = 16.0; H = 1.00)
- A. 464.30 cm3
- B. 625.00 cm3
- C. 1000.00 cm3
- D. 2153.80 cm3
Consider the reaction represented by the following equation: C\(_2\)H\(_2\) + yH\(_2\) → C\(_2\)H\(_6\). The value of y in the reaction is
- A. 4
- B. 3
- C. 2
- D. 1
Which of the following statements about nuclear reaction is correct? The reaction
- A. involves neutrons only
- B. takes place inside the nucleus
- C. is governed by temperature and pressure
- D. involves protons and electrons only
Noble gas molecules are held together by
- A. van der Waals forces
- B. hydrogen bonds
- C. dative bonds
- D. covalent bonds
Which of the following elements is diatomic?
- A. Sodium
- B. Oxygen
- C. Iron
- D. Neon
The bonds in crystalline ammonium chloride are
- A. covalent and dative
- B. ionic and covalent
- C. ionic, covalent and dative
- D. ionic, covalent and hydrogen bond